變數的傳遞

 int volt=5;

int analog_pin=1;

int led_pin=2;

int value;

float volt_value;

void setup() 

{

 Serial.begin(9600);

 pinMode(led_pin,OUTPUT);

}

void loop() 

{ 

 value=analogRead(analog_pin);

 volt_value=(float)value*volt/1024;//變數的傳遞

 Serial.print("電壓為");

 Serial.print(volt_value);

 Serial.println("伏特");

 if(volt_value>2.5)

  digitalWrite(led_pin,HIGH);

 else

  digitalWrite(led_pin,LOW);

}